This invention relates to a method of mounting fuse holding clips for a fuse holder on a circuit board and more particularly an improvement on a method of mounting fuse holding clips by an automatic part inserter after they are cut away from a lead frame including a plurality of fuse holding clips having mounting legs to extend through mounting holes in the circuit board and to be securely mounted on the circuit board by a soldering layer.
In general, there has been used an automatic part inserting machine which mechanically inserts a plurality of fuse holding clips at their mounting legs in mounting holes in a circuit board in a continuous manner.
There has been also used an assembly of fuse holding clips to be mounted on the circuit board by such an automatic part inserting machine. Such an assembly of fuse holding clips may be referred to as taped clips and comprises a lead frame having a perforation engaging feeding pawls of a sprocket of the automatic part inserter with the fuse holding clips at their mounting legs integrally extending from the lead frame in a spaced manner.
Each of the fuse holding clips comprises a resiliently fuse holding clip body including mounting legs integrally provided thereon. The clip body comprises a generally U-shaped curved piece for resiliently holding one of bases of a fuse such as a cartridge fuse and an upper base receiving opening provided at the end of the curved piece and widened toward its upper edges.
The automatic part inserting machine feeds the taped clips to a clip mounting position by rotation of its sprocket and removes the respective fuse holding clips at their mounting legs out of the taped clips by holding them by means of a chuck of the machine and cutting them by means of a cutter thereof.
Thereafter, the machine pushes down the respective fuse holding clips by a pusher of the machine while inserting the mounting legs of the fuse holding clips into the mounting holes in the circuit board until an outer bottom of the U-shaped curved piece engages the upper face of the circuit board.
Finally, the mounting legs of the fuse holding clip are clinched by a clincher of the machine so that they are bent along an underside side of the circuit board toward an electrically conducting layer thereon and soldered thereto so that they are electrically and mechanically connected to the electrically conducting layer.
As shown in FIG. 18, such fuse holding clips 12 have a pawl-like base engaging tab 26 provided on the clip body and serving as a stop so that the cartridge fuse 45 held by the fuse holder is never axially removed out of the fuse holder.
This means that the fuse holding clips 12 have to be mounted on the circuit board 36 in such a correct direction as the base engaging tab 26 of the faced fuse holding clips 12 and 12 are disposed outside the fuse held by the fuse holder in a symmetrical manner as shown in FIG. 18.
However, the mounting legs (not shown) of the fuse holding clips 12 are provided along their axis in a spaced manner regardless of the direction in which the fuse holding clips 12 are to be mounted. Thus, if the insertion program or a cartridge in which the fuse holding clip assembly is contained is set in a reverse direction, then the fuse holding clips 12 are mounted in an incorrect direction as shown in FIG. 20.
This disables the cartridge fuse 46 to be held by the fuse holder because the base engaging tabs 26 prevent the fuse 46 from being inserted into the fuse holding clips 12.
Furthermore, in this case, since the fuse holding clips 12 should be removed out of the circuit board and again mounted thereon, the operation of mounting the fuse holder is disadvantageously troublesome.